1. Field of the Invention
The present invention relates to apparatus for the low cost, rapid retrieval of information relating to a plurality of variable quantities that have their status or condition displayed by a plurality of visual indicators having a particular positional relationship with respect to one another, in general, and to such apparatus for the retrieval of information relating to process control or other equipment, in particular.
2. Description of the Prior Art
A variety of equipments in general and certain process machinery in particular, are often provided with a plurality of indicators that visually indicate the status and/or condition of certain variable quantities that are either within or are associated with said equipments. As a result of the limited space that is alloted to visual indicators on a particular piece of equipment, normally only minimal information is provided on or near such indicators to explain the meaning associated with an indication by a particular variable quantity displaying visual indicator. Placing a sizable amount of information on, or in relatively close proximity to, a particular visual indicator is normally impracticable due to said space limitation.
If a machine operator is thoroughly familiar with the operation and/or servicing of a particular machine, a minimum amount of information on or near the visual indicators displaying the status and/or condition of certain variable quantities essentia to proper machine operation would normally be adequate. However, a novice machine operator not familiar with the operation of such a machine will need ready access to relatively detailed, machine operating and servicing information. In the case of process machinery in particular, a delay in obtaining such information can be costly in terms of reduced machine output or lost production
One arrangement that would provide rapid ready access to visual indicator related machine operating and/or servicing information could be a computer with a video display where all of the necessary operating and servicing information relating to said indicator is stored in said computer for subsequent viewing on said video display. The information could either be manually selected for viewing on the video display by a machine operator or the information could be automatically selected for viewing on said video display in response to an indication by the indicator to which such information relates. In either case, the equipment associated with this particular type of information retrieval, and the updating of such information is relatively costly. Other information retrieval apparatus that provide relatively rapid access to necessary machine operating and servicing information necessarily entails a substantial equipment acquisition and information updating cost penalty. Information retrieval apparatus that does not provide the necessary rapid access to information will produce increased production costs because of the increase in information retrieval time.